This description relates to chest protectors.
Commotio cordis is a syndrome in which a blunt impact to the chest causes life threatening ventricular fibrillation (an irregularity in the rhythm and force of the heartbeat), which may lead to sudden death without structural damage to the heart. Commotio cordis most commonly occurs in sports such as baseball, lacrosse, softball, and hockey, when a ball or puck impacts the front, midline chest in the area superficial to the left ventricle of the heart at about 40 mph (17.88 m/s). In some cases, commotio cordis happens when the impact occurs at 20 milliseconds before the T wave portion of a heartbeat, when the heart is undergoing repolarization, or restoring its energy to pump again. The impact causes the heart to enter a ventricular fibrillation rhythm that causes ineffective pumping, and in some cases, sudden death
Since 1998, there have been 156 deaths in the United States attributed to commotio cordis. See Link, Mark S., “Mechanically induced sudden death in chest wall impact (commotio cordis),” Progress in Biophysics and Molecular biology, 82 (2003), pages 175-186. According to a study at Tufts University in 2003, led by Barry Maron, who researched 128 confirmed cases of commotio cordis that were entered into the United States Commotio Cordis Registry, the overall survival rate of commotio cordis was about 16%. Of the 128 cases, 95% were males. The mean age of the commotio cordis victims was 13.6 years, and only about 22% of the victims were greater than 18 years old.
A number of chest protectors have been developed in the past. For example, U.S. Pat. No. 5,742,947 describes an adjustable chest protector that is designed to cover the heart area of a human body, and U.S. Pat. No. 6,748,601 describes an articulating body protective device that includes a fabric outer garment and protective elements.